The one-step fabrication of porous hASC-laden GelMa constructs using a handheld printing system.

The fabrication of highly porous cell-loaded structures in tissue engineering applications has been a challenging issue because non-porous cell-laden struts can cause severe cell necrosis in the middle region owing to poor transport of nutrients and oxygen. In this study, we propose a versatile handheld 3D printer for the effective fabrication of porous cell-laden methacrylated gelatin (GelMa) with high porosity (≈97%) by air injection and a bubble-making system using mesh filters through which a mixture of air/GelMa bioink is passed. In particular, the pore size and foamability of the cell constructs could be manipulated using various processing parameters (rheological properties of GelMa, filter size and number, and air-bioink volume ratio).

Shape-memory collagen scaffold combined with hyaluronic acid for repairing intervertebral disc.

Background: Intervertebral disc degeneration (IVDD) is a common cause of chronic low back pain (LBP) and a socioeconomic burden worldwide. Conservative therapies and surgical treatments provide only symptomatic pain relief without promoting intervertebral disc (IVD) regeneration. Therefore, the clinical demand for disc regenerative therapies for disc repair is high.

Mechanically and biologically enhanced 3D-printed HA/PLLA/dECM biocomposites for bone tissue engineering.

Poly (L-lactic acid) (PLLA)-based biocomposites have been used in tissue engineering applications because of their reasonable biocompatibility and mechanical properties. However, the imperfect bioactive and mechanical properties of the composite make it difficult to be used in the region of bone defects that require high load-bearing. Therefore, this study introduced two fabricating strategies to induce mechanically and biologically enhanced hydroxyapatite (HA)/PLLA biocomposites.

Wound healing ability of acellular fish skin and bovine collagen grafts for split-thickness donor sites in burn patients: Characterization of acellular grafts and clinical application.

Due to its high polyunsaturated fatty acid content, acellular fish skin has emerged as a dermal substitute for the promotion of wound healing as it decreases scar formation while providing pain relief. However, various systematic studies on acellular fish skin, such as its biophysical analysis, in vitro activities, and clinical application, have not been sufficiently investigated. In this study, we conducted a comparative study to evaluate the wound-healing ability of acellular fish skin graft (Kerecis®) with that of the widely used bovine collagen skin graft (ProHeal®).

Self-aligned myofibers in 3D bioprinted extracellular matrix-based construct accelerate skeletal muscle function restoration.

To achieve rapid skeletal muscle function restoration, many attempts have been made to bioengineer functional muscle constructs by employing physical, biochemical, or biological cues. Here, we develop a self-aligned skeletal muscle construct by printing a photo-crosslinkable skeletal muscle extracellular matrix-derived bioink together with poly(vinyl alcohol) that contains human muscle progenitor cells. To induce the self-alignment of human muscle progenitor cells, uniaxially aligned micro-topographical structure in the printed constructs is created by a fibrillation/leaching of poly(vinyl alcohol) after the printing process.

New Bioink Derived from Neonatal Chicken Bone Marrow Cells and Its 3D-Bioprinted Niche for Osteogenic Stimulators.

This study examined whether neonatal chicken bone marrow cells (cBMCs) could support the osteogenesis of human stromal cells in a three-dimensional (3D) extracellular bioprinting niche. The majority (>95%) of 4-day-old cBMCs subcultured 5 times were positive for osteochondrogenesis-related genes (, , , aggrecan, , osterix, , osteocalcin, , and osteopontin) and their related proteins (Sox9, collagen type I, and collagen type II). LC-MS/MS analysis demonstrated that cBMC-conditioned medium (c-medium) contained proteins related to bone regeneration, such as periostin and members of the TGF-β family.

Enhanced healing of rat calvarial defects with 3D printed calcium-deficient hydroxyapatite/collagen/bone morphogenetic protein 2 scaffolds.

In this paper, we mainly to evaluate the newly formed bone using the Calcium deficient hydroxyapatite (CDHA)/collagen-based bio-ceramic scaffold as Bone Morphogenetic Protein-2 (BMP-2) carrier in rat calvarial critical-sized bone defect. In the real-time PCR analysis, the CDHA/collagen scaffold loaded rhBMP-2 group showed significantly enhanced results of bone-related gene expression (p < 0.05).

Efficient myotube formation in 3D bioprinted tissue construct by biochemical and topographical cues.

Biochemical and biophysical cues directly affect cell morphology, adhesion, proliferation, and phenotype, as well as differentiation; thus, they have been commonly utilized for designing and developing biomaterial systems for tissue engineering applications. To bioengineer skeletal muscle tissues, the efficient and stable formation of aligned fibrous multinucleated myotubes is essential. To achieve this goal, we employed a decellularized extracellular matrix (dECM) as a biochemical component and a modified three-dimensional (3D) cell-printing process to produce an in situ uniaxially aligned/micro-topographical structure.

Effect of Hierarchical Scaffold Consisting of Aligned dECM Nanofibers and Poly(lactide--glycolide) Struts on the Orientation and Maturation of Human Muscle Progenitor Cells.

Extracellular matrices (ECMs) derived from tissues and decellularized are widely used as biomaterials in tissue engineering applications because they encompass tissue-specific biological and physical cues. In this study, we utilized a solubilized decellularized tissue (dECM) obtained from skeletal muscle to fabricate a nanofibrous structure using the electrospinning technique. The dECM was chemically modified by methacrylate reaction (dECM-MA) to improve the structural stability before electrospinning.

Skeletal myotube formation enhanced through fibrillated collagen nanofibers coated on a 3D-printed polycaprolactone surface.

This work focused on considering the cellular responses of the growth and differentiation of myoblasts, C2C12, on fibrillated collagen-coated poly(ε-caprolactone) (PCL) surfaces. Through a fibrillation processing window using NaCl and collagen weight fractions, collagen fibril coating density can be controlled. Three different collagen-fibril densities coated on PCL strut were used to investigate the effects of the collagen fibril on the myoblast activities.

The fabrication of uniaxially aligned micro-textured polycaprolactone struts and application for skeletal muscle tissue regeneration.

One of the most important factors in skeletal muscle tissue regeneration is the alignment of muscle cells to mimic the native tissue. In this study, we developed a PCL-based scaffold with uniaxially aligned surface topography by stretching a 3D-printed scaffold. We examined the formation of aligned patterns by stretching the samples at different temperatures and stretching rates.

Three-Dimensional Hierarchical Nanofibrous Collagen Scaffold Fabricated Using Fibrillated Collagen and Pluronic F-127 for Regenerating Bone Tissue.

It is well known that a nanoscale fibrous structure can provide a unique stage for encouraging reasonable cell activities including attachment and proliferation owing to its similar topological structure to the extracellular matrix. Hence, the structure has been widely applied in tissue regeneration. Type-I collagen has been typically used as a typical tissue regenerative material owing to its biocompatibility and abundance, although it has potential for antigenicity.

Calcium-Deficient Hydroxyapatite/Collagen/Platelet-Rich Plasma Scaffold with Controlled Release Function for Hard Tissue Regeneration.

Calcium phosphate cement scaffolds have been extensively used in bone tissue regeneration applications because they are similar to the inorganic components of bones and have outstanding biocompatibility. However, the main shortcomings of ceramic scaffolds are their brittleness and low retention level of various growth factors or drugs. To overcome these shortcomings, we have reinforced ceramic scaffolds using synthetic and natural polymers as composites.

Development of a tannic acid cross-linking process for obtaining 3D porous cell-laden collagen structure.

Cell-printing is an emerging technique that enables to build a customized structure using biomaterials and living cells for various biomedical applications. In many biomaterials, alginate has been widely used for rapid gelation, low cost, and relatively high processability. However, biocompatibilities enhancing cell adhesion and proliferation were limited, so that, to overcome this problem, an outstanding alternative, collagen, has been extensively investigated.

Preparation and characterization of gelatin/α-TCP/SF biocomposite scaffold for bone tissue regeneration.

In this study, we suggest a new biocomposite scaffold composed of gelatin/α-TCP (tricalcium phosphate)/SF (silk-fibroin) (GTS) which has enhanced mechanical strength and high level of cellular activity. To fabricate GTS scaffold, a temperature-controlled 3D printing process was used and appropriate printing conditions were selected based on rheological data. To show the feasibility as a biomedical scaffold for bone tissue regeneration, the various physical and biological results, using MG63 (osteoblast-like cells), of the GTS scaffold were compared with those of a pure gelatin (G) and gelatin/α-TCP (GT) composite scaffold.

Change in Renal Function among HIV-Infected Koreans Receiving Tenofovir Disoproxil Fumarate-Backbone Antiretroviral Therapy: A 3-Year Follow-Up Study.

Purpose: Tenofovir disoproxil fumarate (TDF) is commonly prescribed as a fixed-dose, co-formulated antiretroviral drug for HIV-1 infection. The major concern of long-term TDF use is renal dysfunction. However, little is known about the long-term patterns of changes in renal function in HIV-infected Koreans receiving TDF.

Long Pentraxin 3 as a Predictive Marker of Mortality in Severe Septic Patients Who Received Successful Early Goal-Directed Therapy.

Purpose: Pentraxin 3 (PTX3) has been suggested to be a prognostic marker of mortality in severe sepsis. Currently, there are limited data on biomarkers including PTX3 that can be used to predict mortality in severe sepsis patients who have undergone successful initial resuscitation through early goal-directed therapy (EGDT).

Materials And Methods: A prospective cohort study was conducted among 83 severe sepsis patients with fulfillment of all EGDT components and the achievement of final goal.

Predictive factors for unfavorable outcomes of tuberculous pericarditis in human immunodeficiency virus-uninfected patients in an intermediate tuberculosis burden country.

Background: In areas where Mycobacterium tuberculosis is endemic, tuberculosis is known to be the most common cause of pericarditis. However, the difficulty in diagnosis may lead to late complications such as constrictive pericarditis and increased mortality. Therefore, identification of patients at a high risk for poor prognosis, and prompt initiation of treatment are important in the outcome of TB pericarditis.

Delaying diagnostic procedure significantly increases mortality in patients with invasive mucormycosis.

Invasive mucormycosis is an uncommon but increasing life-threatening fungal infection. The present study investigated clinical characteristics and mortality among patients diagnosed as invasive mucormycosis infection. We retrospectively reviewed a total of 24 histologically proven cases of invasive mucormycosis at two tertiary care referral hospitals between November 2005 and February 2014.

The simple predictors of pseudomembranous colitis in patients with hospital-acquired diarrhea: a prospective observational study.

Background/aims: As the incidence rate of and mortality from pseudomembranous colitis (PMC) are increasing worldwide, it is important to study the simple predictive risk factors for PMC among patients with hospital-acquired diarrhea (HAD). This study focused on identifying the clinical risk factors that can easily predict PMC.

Methods: The presumed HAD patients were prospectively recruited at the Hallym University Kangdong Sacred Heart Hospital.